Field of the Invention
The present invention relates to a technique of handling tomograms.
Description of the Related Art
In the medical field, a doctor makes a diagnosis by using the medical images (three-dimensional image data representing three-dimensional information inside an object) captured by a plurality of modalities or medical images captured on different dates. In order to use a plurality of types of medical images for a diagnosis, it is important to associate (identify) a region (a region or lesion of interest) such as a lesion of interest on each medical image. For this reason, the doctor searches for a region (a corresponding region or lesion) corresponding to a lesion of interest pointed out on one medical image from another medical image by using, as clues, similarities in terms of the shape of the lesion, the appearance of a neighboring portion of the lesion, and the like, while seeing the image of the lesion of interest.
In a breast oncology department, after a lesion or the like on an MRI image of the breast imaged in a prone posture is pointed out, a doctor sometimes makes a diagnosis upon searching for (identifying) a corresponding lesion on an ultrasonic tomogram by an ultrasonic examination in a supine posture. However, since the breast as an object is soft and large differences appear between body postures, the position and appearance of a lesion greatly change. This makes it difficult to search for a corresponding lesion. Demands have therefore arisen for a reduction in load by some kind of computer aid.
Patent literature 1 (Japanese Patent Laid-Open No. 2011-123682) discloses a technique of estimating the deformation of the breast from a prone posture to a supine posture. Using this deformation estimation result can estimate the position of a lesion in a supine posture and present the estimated position as support information for the operation of an ultrasonic probe. In addition, patent literature 2 (Japanese Patent Laid-Open No. 2010-227215) discloses a technique of automatically extracting a nipple position from a simple X-ray image of the breast and drawing a region in an image which is included in a predetermined range from the nipple position in the image.
When using the method disclosed in patent literature 1, since it is necessary to perform calculation for a deformation simulation such as a finite element method, the operator (doctor) needs to wait until the end of the calculation. In addition, there are several types of measurement information which the operator should input for the execution of a deformation simulation, but the operator is sometimes not allowed to take time and effort to input such information. In addition, it is not easy to accurately estimate the deformation of the breast itself. In addition, the method disclosed in patent literature 2 allows the operator to know a region within a predetermined range from a feature point of an object. This region is limited to only a slice including the feature point in the image. It is therefore impossible to know the region on an arbitrary slice.